Anyone give some insight on 300 Blk Out Pistol setup? Wanting to set it up for deer hunting. Any ammo/scope setups would be appreciated.

Are you going to shoot subs or supersonic ammo? I keep an RMR on my 9.5” pistol. A LPVO is another option but with braces being banned/in limbo they are more difficult to use effectively. I tend toward supers for deer. I like the Barnes Vortex 110 or 120(when I can find them). I found some S&B or PPU 120s, I can’t recall at the moment who made them, but the bullet construction was very similar to the Barnes. I haven’t gotten to try them yet. For subs I use the Hornady A-max and I have some custom Makers rounds.
But I mostly use my pistol with hogs and 147gr FMJ out of deer season.

If you aren't gonna suppress it get the 16in rifle

Well you sort of have to until the line change the law.

However, I must disagree with you if the laws change. Yes the 16” performs better but the .300blk is designed to burn all powder out by 10.5”. Therefore, you don’t have much muzzle blast post 10.5” and you do not lose a ton of velocity. A pistol length .300blk lays nicely in your lap when in a tree stand. For ammo the 110 or 120ttsx performance is great! As far as optics go, I am a glass snob so I always get all I can!

Meh there isn't a brace law you get around 200fps more mv with supersonic in a 16in and it's not as loud as a 10.5 unsuppressed. OP unless you are planning on suppressing the bo I'd go with the 350 legend for a short range AR platform.

Shot one with the vortex a couple years ago, not a huge blood trail but he was dead within 50 yards. To my surprise the .300 pistol is very accurate to 100 yards probably more ive just never tried any further. Nikon 3x32 scope, but if I had my pick I would put a leupold freedom 2-7x33 on it

LOL….most anything factory on a 223-size case ‘burns all the powder’ in well under 16”. The issue is how much velocity did the bullet get from that pressure curve WITHIN the barrel length you’re after? I can tell you this: the less shoulder a case has and the larger the bore, the more ‘efficient’ it is in short barrels, or longer. I’ve got 10.5” 7.62x39 stuff and 13” 223/5.56 stuff. There’s more blast from the 7.62x39 than a similar 300BO, and the BO is more efficient….but for shooting supers and terminal performance, the x39 gives more in that barrel than the 300. A 357 AR Max would be about as efficient as you’ll get on the 223/5.56 case, with the 350 Almost and it’s 9mm case coming in second. If you want to jump up, the 400 Legend would likely be a pretty strong contender for most well-rounded and efficient in an AR-15, that’s still kid friendly.

Is the 300 Blackout the best all round deer caliber? Probably not. I had a shoulder surgery just before the season last year so I ran my braced pistol with Barnes 110gr Tac-X and a Leupold 3-9x40. It went 3 for 3. We would have to work to have a shot beyond 130 yds or so, which to me makes it viable. What I liked was basically handling it one handed on the way to and in the shooting house. Its short length was also nice in smaller houses. What I don’t like about hunting with the AR is that it’s hard to cycle the action quietly and I feel like the metallic clang carries a long way. Because of the extra length and weight I left the suppressor at home. If I find a deal on a Ruger American in 300 Blackout, I just might grab one.

BTW federal judge overturned the pistol brace ATF horsecrap! Just yesterday so build away!!!